Here is a simple way to think about what might alter the expected branching ratio products from (say) d+d fusion to result in the "little or no high energy products" characteristic of most LENR experiments otherwise claimed positive.

http://sjbyrnes.com/cf/branching-ratio-collective-effects/

If you agree with this argument it rules out a number of theories simply - and on grounds that are very fundamental.

It is an application of the "nuclear reactions are hard to influence because they occur at such very short time and space scales" principle.

Decay reactions of nearly stable nuclei have long time scales, but all have small space scales hence not much can get close, just electric and magnetic fields

Most fusion reactions also have very short time scales because the intermediate fused particle, carrying lots of extra energy from the fusion, has very short lifetime.

Short reaction time => limited number of things can influence the reaction (from relativity).

So: who agrees with it? Who disagrees (and if so what is the loophole). Who reckons their favourite fusion happens theory avoids it?

Quote from axil

“No information or influence can travel faster than light.”

How about entanglement?

http://newatlas.com/quantum-en…10000-faster-light/26587/

Quantum "spooky action at a distance" travels at least 10,000 times faster than light

When entities become entangled (as in a bose condinsate)speed and distance does not apply.

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No - entanglement does not provide any causal connection - specifically it cannot transfer information or energy FTL.

Quote from axil

Or here’s another example. Two deuterons bouncing around at room temperature do not have enough energy to surmount the Coulomb barrier and fuse. But what if a million deuterons pooled their energy together, spontaneously transferring it all to a single deuteron? Actually this particular example is just wishful thinking. Atoms don’t do that, it would violate the second law of thermodynamics. I chose this example to illustrate how easily one can dream up collective effects that, upon closer scrutiny, are inconsistent with the laws of physics!

This assertion is not quite correct.

Superradiance

https://en.wikipedia.org/wiki/Superradiance

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Axil - the OP is I think correct (I can't find any error) and your counterexample is certainly different. Transferring distributed energy to a single deuteron reduces entropy. Coherent emission, in which stimulated emission creates a coherent wave (lots of photons) does not decrease entropy and so is OK. It is true that coherent radiation has lower entropy than incoherent, but from metastable states in separated atoms to coherent photons does not decrease entropy. In fact it increases entropy because the atom population moves closer to a less ordered equilibrium state.

Quote from axil

https://www.technologyreview.c…overcomes-distance-limit/

"Instead of relying on entangled regions of space to balance the energy between one point and another, the squeezed state itself does the balancing. And that makes it possible to teleport energy over almost any distance."

https://phys.org/news/2014-01-…ort-energy-distances.html

"a theory they've developed that takes advantage of the properties of squeezed light or vacuum states to allow for "teleporting" information about an energy state, allowing for making use of that energy—in essence, teleporting energy over long distances."



"Quantum mechanics laws limit the ways that values in a system (such as a vacuum) can be measured—physicists have found however, that increasing the uncertainty of one value, decrease the uncertainty of the value of others—a sort of squeezing effect. When applied to light, theory suggests, it leads to more pairs traveling together through a vacuum, which in turn leads to more of them being entanglement, and that the team suggests should allow for teleporting energy"

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Good try Axil.

This does allow energy teleportation but ONLY sub-speed-of-light. I should have qualified my statement as "transfer of energy between spatially separated events" which is what I meant, and what you need for this argument to work.

The key part of the paper is here:

Assuming that Bob receives the information of µ from
Alice at time t = T , Bob then performs an instantaneous
unitary operation dependent on µ given by

[Eqn (4) from paper]

Basically Alice and Bob (the two spatially separated observers) can teleport energy by a sequence - read the paper for more details:

(1) Bob creates a squeezed vacuum state wave moving to Alice

(2) Alice measures this, resulting in a single bit, and the entangled state now correlated with this

(3) Alice sends the bit mu she measured (as information, no energy) to Bob

(4) Bob performs a measurement on the entangled state that depends on mu

As result of this sequence energy is is inserted into the squeezed vacuum wave at Alice location (in step 2) and extracted from the wave at Bob's location (in step 4). However the process takes at least time L/c where L is the Alice/Bob separation from step 3.

QET is interesting, but only works here because it is using correlations in the quantum vacuum state (Casimir effect type stuff - very low level). As such over macroscopic distances it obeys causality. If we had any instantaneous energy transfer that would necessarily mean instantaneous information transfer and we could set up time paradoxes easily by signalling to the past. the universe seems to be set up to protect itself from that at a deep level.

THH

Quote from JulianBianchi

THHuxleynew

Thank you for this thread and the interesting link. I agree that many theories are ruled out on this simple "short time and space scales" principle. This basic principle is precisely the reason why I have a strong interest in Ultra Dense Hydrogen. In practice, all data on the excited state He4* published in the review by Tilley, Weller & Hale, 1992, come from experiments with D atoms impinging other D atoms at a given kinetic energy. AFAIK the lowest kinetic energy ever used was as low as 2 keV in an experiment performed at the Mines in collaboration with the LANL (see Wilkinson & Cecil, 1985; Cecil & Hale 1991). Of course, at such low kinetic energy levels, the yields of the usual D(d,p)T and D(d,n)3He reactions decrease drastically. However, the rates are still high enough to show that the branching ratio remains constant independently of the COM energy (see Cecil & Hale 1991, 2nd Conference on Cold Fusion). These results were viewed by many physicists as conclusive evidence that "Cold Fusion was crap".

In D beams experiments, the time two D nuclei are in close vicinity is short. The kinetic energy of the impinging D is mainly used to pass the Coulomb barrier with a short "dwell time" for quantum tunneling. Things are radically different with UDD where the time scale is very long (> 1sec) and the space scale is short (~10-12m). Meaning that the time and space scale conditions are fulfilled for the weak interaction to play a role. Of course these long time and short space scales don't say why the usual fast decay of the He4* doesn't appear to occur. However, UDD is a state of zero orbital angular momentum, therefore of positive orbital parity. As nicely pointed out by Schwinger as early as in 1989, if He4* is in a s-state of even orbital parity, this state cannot involve electric dipole radiation or an odd-parity particle to reach a ground state with even parity. The usually dominant electric dipole radiation, which requires a parity change, is therefore forbidden. Of course, at that time, Schwinger didn't know about the (possible) existence of UDD and that UDD has zero orbital angular momentum by its very nature. Interestingly, he still posited the existence of a 4th branch with all energy transferred to phonon excitations in the Pd-D lattice, but I think that even himself viewed his explanation as far-fetched.

Actually, if the usual branches are forbidden, the main branch may be the decay of He4* to mesons via the weak interaction, knowing that the conservation of the baryon number is an approximate law only. Interestingly, the possible existence of this 4th branch is based on the same time and scale principles as used in the link you provided. Some may argue that to have mesons rather than protons and neutrons as products of the fusion is just shifting the problem. However it happens that the mesons resulting from the decay of He4* would have a kinetic energy close to the minimum of the Bethe-Bloch curve (and still assuming a charge particle such as K-), therefore they would be difficult to detect almost by definition.

In short, the existence of UDD may (does?) solve the paradox you mention. In that regard, it is often claimed that the work of Holmlid has never been replicated. On the contrary, one should not forget that the first experimental evidence of UDD came from Lipson et al, 2005, a Cold Fusion experiment by the way, with then Holmlid providing further experimental evidence of its reality.

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So, I agree UDD is an interesting idea that changes various things. I liked it when Holmlid first proposed evidence for this - with some limited theoretical support - and much less when it then morphed into UDH as well (where the theoretical support did not seem to work). That is a judgement of whether Holmlid's evidence looks coherent or not, and separate from the theoretical considerations here.

The key issue is what time is available for dispersal of the fusion energy. You are considering the time over which the fusion reaction can happen. But throughout this there is no excess energy to disperse. the dispersal happens only after the D nuclei (through tunnelling) have got close enough to fuse. At that point we have the nucleons together in an He4 structure that releases much binding energy, and hence is in an excited state. That excited state is unstable and so gets rid of its energy quickly, one way of another. and the lifetime of that excited He4 state is low. True, it will depend on the total excitation energy, which will be the large amount released by fusion + or - a contribution from the original kinetic + potential energy of the fusing particles. (This can be negative because of tunelling). However, the energy released (10s of MeV) is far larger than the Coulomb barrier energy (100s of kEv), so it would be unlikely for that to have a large affect on the stability of the excited He4 nucleus.

A bose condensate is a single entity in which rules of thermodynamics is not applicable. A Bose condinsate is a dual of a black hole in which all of the behaviors of black holes apply to the condinsate, this includes hawking radiation. The detection of tachyon tracks in LENR works to validate this principle.

(1) I don't accept that tachyon tracks have been positively detected in LENR. Rather, some experiments have data which has been interpreted by some people as tachyon tracks. So that does not validate your statement, unless the evidence can only be interpreted as tachyon tracks. Even then we are back to replicability etc.

(2) The rules of thermodynamics do apply to BECs. However since the constituent particles are all by definition in the BEC ground state by definition they have the lowest possible entropy (for state transitions possible during the BEC lifetime - there may of course be other state transitions that break the BEC).

(3) I don't see how you propose that a BEC should solve this time/distance problem. You would need high overlap between the BEC wave function and the He4* nucleus, and possible higher energy states for the BEC constituents, and transitions to absorb the energy. The only overlap I can see is with photons - but then photons are bosons anyway, you do not need a BEC to have a high local photon density! However, I'm open to suggestions.

To get round the OP objection here, you need to hypothesise that something about LENR d+d reactions (if that is what they are) means the intermediate He4* nucleus formed is much more stable than normally found to be the case, so there is time enough for some novel energy dispersal mechanism. I can't see any other way round it.

Quote from axil

The reason why the referenced paper is invalid is because the fundamental assumption that the paper is based on is invalid. Specifically, LENR has nothing to do with fusion. You just can't build anything on bad ground and that is what this paper is doing, it is building an argument on nobsence. Prove that fusion is producing transmutations and isotope shifts in LENR. The referenced paper is assuming that the assertion of fusion as fact when that conjecture is false. Proton proton fusion as a nuclear reaction is extremely low in its activity. You will never see any proof that that kind of fusion is occurring. And where are the neutrons?

So, that is fine, but it is not an alternative unless you propose the specific (nuclear) non-fusion reaction that you propose is happening? The same applies to Eric - though I realise he has a specific reaction in mind. Then we can revisit things: because there might still be an energy dispersal issue.

BTW I think the common proposal here is deuteron-deuteron fusion - not p-p fusion.

Thus far your argument aligns with that of Shanahan (LENR is no nuclear reaction at all).

Quote from JulianBianchi

[see below]

Not sure I understand what you mean given that UDH and UDD is virtually the same beast (except for the additional neutrons of course).

Originally Holmlid with theoretical support from Winterberg suggested that a Madelung transformation of the QM wave function - only possible for deuterium - could result in the high density:

An attempt is made to explain the recently reported occurrence of 14 MeV neutron induced nuclear reactions in deuterium metal hydrides as the manifestation of a slightly radioactive ultra-dense form of deuterium, with a density of 130,000 g/cm3 observed by a Swedish research group through the collapse of deuterium Rydberg matter. In accordance with this observation it is proposed that a large number of deuterons form a “linear-atom” supermolecule. By the Madelung transformation of the Schrödinger equation, the linear deuterium supermolecule can be described by a quantized line vortex. A vortex lattice made up of many such supermolecules is possible only with deuterium, because deuterons are bosons, and the same is true for the electrons, which by the electron–phonon interaction in a vortex lattice form Cooper pairs. It is conjectured that the latent heat released by the collapse into the ultra-dense state has been misinterpreted as cold fusion. Hot fusion though, is here possible through the fast ignition of a thermonuclear detonation wave from a hot spot made with a 1 kJ 10 petawatt laser in a thin slice of the ultra-dense deuterium.

No. Not only. I specifically addressed the point why the usual fast decay involving electric dipole radiation is forbidden. (Not saying that the differentiation of the dwell time from the lifetime of the metastable state, as you did, is now considered obsolete, but this is another issue).

My understanding is that the n or p ejection decay mechanism is even faster - otherwise it would not normally have a higher branching ratio. So all of the known decay paths are fast as stated in the OP link (with numbers derived from the gamma line width which therefore bounds the state existence time).

Again, not sure I understand what you mean by "got close enough". Because neither tunnelling brings the D nuclei "close enough to fuse" nor the distance between the two D atoms of UDD is changing over time.

Yes, I understand that. But it does not matter since while that affects things pre-fusion, it does not change the dynamics post-fusion.

What is "quick" for you when the fast decay via the strong interaction is forbidden? Please specify.

< 10E-21 seconds

How much? Again you make a vague statement here, please specify.

< 10E-21 seconds

UDD is characterised by zero kinetic energy and zero orbital angular momentum therefore you make a moot point.

In this case the incoming K.E. is zero. The point is that the mass of He4 is less than that of d+d and that mass deficit turns into energy in the excited He4*. 23.8MeV. Or, if you consider energy above the necleon ejected product states, 3.3 or 4.0 MeV.

Again you make a vague statement without specifying the decay you are talking about. In practice the energy release of the various decays discussed in the thread differ by more than 2 orders of magnitude. Also, to link the amount of energy release and the Coulomb barrier energy to the stability of He4* doesn't make sense to me.

I agree that the known timescale of these reactions is more convincing than any theoretical argument.

Quote from Alan Smith

OK. Neither do I. What do you think the 'corkscrew' particle tracks are then?

Alan, I don't wish to make a case for what these tracks are, since I feel it would be uninformed. That applies to a large number of observations...

I'm sure there are people around who are in a better position to do so.

If we are to suppose these come from some high energy charged particle (where the velocity / charge ratio can be determined from the track shape) then I can suggest candidates:

(1) Radon progeny emissions

(2) GCR

I'm not in a position to say which of these are plausible in this case, nor whether there might not be some other candidate.